There exists concern about pathogenic and enteric bacteria in animal meat, and, in particular, ground beef. As a consequence of processing animals into meat for human consumption, the surface of the animal carcass may become contaminated with bacteria from many sources including processing equipment, workers, and the environment. The predominant source for bacterial contamination is the animal itself. The hide, hooves, intestinal contents, and milk have the potential to harbor not only large numbers of bacteria but also pathogenic bacteria. Techniques have been utilized for reducing bacterial contamination of the animal carcass. For example, International Publication No. WO 96/13983 describes an apparatus for steam pasteurization of the surface of meat carcasses. Other techniques for reducing the contamination of the carcass surface involves trimming defined areas on the carcass, and washing the carcass with both hot and cold water. These techniques are described by Phebus et al., “Comparison of Steamed Pasteurization and Other Methods for Reduction of Pathogens on Surfaces of Freshly Slaughtered Beef,” Journal of Food Protection, vol. 60, no. 5, 1997, pages 476–484. Techniques for treating buffalo meat cuts from shoulder and leg portion in hot water at 70° C. and 80° C. for 30 to 60 seconds is described by Sachindra et al., “Reduction in Microbial Load on Buffalo Meat By Hot Water Dip Treatment,” Meat Science, vol. 48, no. 1/2, pages 149–157, 1998.
Bacterial populations have the opportunity to form on the exposed carcass surface. A large percentage of the trimmings which are processed for human consumption are obtained from this exposed carcass surface. It has been found that E. coli bacteria, and many pathogens, can reside on the surface of carcass beginning with the carcass processing. The pathogens can originate from fecal matter and other contaminants on the surface of the meat. Without adequately destroying these pathogens, the meat is processed, and shipped to the distributor, retailer, or consumer. It is then left for the consumer or preparer of the meat to address the problem that by then can be even worse. The bacteria may have further multiplied. Ground meats are very susceptible to bacteria growth because the surface pathogens can be distributed throughout the meat during processing.